• F. E. OLAIFA
  • G. R. AKANDE
Keywords: Benzo(a)pyrene, essential amino acids, catfish, smoking, hydrocarbons


Fish food quality and safety is critical to consumers due to its public health implication. To exploit huge export opportunities for smoked farmed catfish, there is need for strict adherence to international quality and safety standards. This paper examined amino acid profile and polycyclic aromatic hydrocarbons (PAHs) of smoked farmed catfish Clarias gariepinus raised under different culture systems with a view to determining its quality and safety. Six farms with the two most common fish culture systems (3 concrete tanks (CTs) and 3 earthen ponds (EPs) were purposively selected based on frequency of harvest and yield. Fish samples (500±10g) obtained from these farms after 4 months of culture were processed, smoked, packaged and stored for 36 weeks. Amino acid profile in farmed fresh and smoked C. gariepinus was determined at 12, 24 and 36 weeks of storage and polycyclic aromatic hydrocarbons (PAH) was determined at 0 and 16 weeks of storage. These were compared with traditional smoked wild catfish obtained from local fish processor (LFP). The amino acids with highest concentrations (mg/g) found in this study were leucine (22.16 - 31.61 and 13.89 – 29.64), lysine (16.31 – 20.19 and 9.86 – 18.08), arginine (15.16 – 12.29 and 8.97 - 15.86), valine (15.96 – 21.35 and 9.68 - 19.36 ) and asparagine (19.66 – 21.61 and 12.36 mg/g – 20.71mg/g) for fresh and smoked catfish respectively. Levels of other amino acids ranged from 1.5mg/g to 9.98mg/g in smoked fish and 2.95mg/g to 12.21mg/g in fresh fish. The mean total poly aromatic hydrocarbons in smoked catfish at 16 weeks of storage were 0.039±0.004µg/kg, 0.034±0.005 µg/kg and 0.053±0.005 µg/kg for EP, CT and LFP, respectively. Therefore smoked farmed catfish raised under different culture systems still contain essential amino acids and Benzo(a)pyrene which is a carcinogen was not at detectable level in the samples.


Ajai A. Ikechukwu, Suleiman M. Tanko, Dauda B. Emmanuel, Sadiku O. Suleiman and Aberuagba, F. 2012: Effect of Extraction Methods on the Polycyclic Aromatic Hydrocarbons Content Smoked Catfish Species in Niger State of Nigeria. Jordan Journal of Biological Sciences 5(1),71 - 80
Anyakora, C and Coker H 2007. Assessment of Polynuclear aromatic hydrocarbon content in four species of fish in Niger Delta by Gas chromatography/ mass spectrometry African Journal of Biotechnology 6, 737-743
Da Silva A. L. V. 2002. Hazard Analysis Critical Control Point (HACCP), Microbial safety and shelf life of smoked Blue Catfish (Ictalurus furcatus). A M.Sc. Thesis submitted to the graduate Faculty of the Louisiana State University and Agricultural and Mechanical College.
Chimezie A and Herbert C. 2006. Determination of polynuclear aromatic hydrocarbons (PAHs) in selected water bodies in the Niger Delta. African J of Biotechnology, 5 (21): 2024-2031.

Easton M.D.L, Luszniak D and Von der Geest E. 2002: Preliminary examination of contaminant loadings in farmed salmon, wild salmon and commercial salmon feed. Chemosphere, 46: 1053-1074.

European Commission (EC) 2011: Draft COMMISSION REGULATION (EU) No …/…of amending Regulation (EC) No. 1881/2006 as regards maximum levels for polycyclic aromatic hydrocarbons in foodstuffs. Brussels, C (2009) SANCO/10616/2009 rev. 7 (11.4.2011)

European Commission 2005 Directive No. 208/2005 of 4 February 2005, amending Regulation (EC) No. 466/2001 as regards polycyclic aromatic hydrocarbons. Official Journal of European Union, Brussels, Belgium
Eyo, A. A. 2001. Fish Processing Technology in the Tropics. University of Ilorin press, Nigeria. 403pp

Garcia-Falcon M. S. G, Amigo G. S, LMA Y, Villaizan M. J, and Lozano S. L 1996. Enrichment of benzo(a)pyrene in smoked food products and determination by high-performance liquid chromatography fluorescence. Journal Chromatograph 753; 207-215.
Ibhadon S, M. S. Abdusalami, M.C. Emere and V. Yilwa 2015: Comparative study of Proximate, Fatty and Amino Acids Composition of Wild and Farmed Raised African Catfish C. gariepinus in Kaduna, Nigeria. Pakistan Journal of Nutrition 14 (1): 56 -61

Ikechukwu A. A, Suleiman M.Tanko, Dauda B.Emmanuel, Sadiku O.Suleiman and Aberuagba, F. 2012: Effect of Extraction Methods on the Polycyclic Aromatic Hydrocarbons Content Smoked Catfish Species in Niger State of Nigeria. Jordan Journal of Biological Sciences Volume 5, Number 1, Pages 71 - 80
Joint FAO/WHO Expert Committee on Food Additives (JECFA) 1987. Evaluation of certain food additives and contamination. WHO Technical Report Series, 31, 759 p

Mohanty B, Mahanty A., Ganguly S, Sankar T. V, Chakraborty K, and Rangasamy A, et al, 2014: Amino Acid Compositions of 27 Food Fishes and Their Importance in Clinical Nutrition Journal of Amino Acids Volume 2014 (2014), Article ID 269797, 7 pages assessed October, 2015

Mičulis J, Valdovska A, Šterna V and J. Zutis 2011: Polycyclic Aromatic Hydrocarbons in Smoked Fish and Meat Agronomy Research 9 (Special Issue II), 439–442

Olabemiwo, O.M; Alade, O.A; Tella, A.C and Adediran, G.O 2011. Assessment of Polycyclic Aromatic Hydrocarbons content in smoked Clarias gariepinus and Tilapia guineensis fish species available in Western Nigeria International Journal of Basic and Applied Sciences IJBAS-IJENS vol.11 No 02 pg. 135-150

Osibona A. O. 2011. Comparative study of proximate composition, amino acids and fatty acids of some economically important fish species in Lagos, Nigeria. African Journal of Food Science 5: 581-588.

Osibona A.O, Kusemiju K. and Akande G. R 2009. Fatty acid composition and Amino acid profile of two Freshwater species, African catfish (Clarias gariepinus) and Tilapia (Tilapia zilli).African Journal of Food Agriculture Aesthetics and Development (AJDFAND online) Vol. 9 No. 1 pp 609 - 621 Assessed 13/8/2012

Silva, B. O; Adetunde O. T.; Oluseyi T. O; Olayinka K.O. and B.I Alo B. I. 2011. Effects of the methods of smoking on the levels of Polycyclic aromatic hydrocarbons (PAHs) in some locally consumed fishes in Nigeria African Journal of Food Science Vol 5(7) pp384-391 July 2011 Retrieved Nov. 2012 from

Usydus, Z., Szlinder-Richert J. and Adamczyk. M. 2009. Protein quality and amino acid profiles of fish products available in Poland. Food Chemistry, 112: 139-145.

Wretling S, Eriksson A, Eskhult G A and Larson B. 2010. Polycyclic aromatic hydrocarbons in Swedish smoked meats and fish. J of Food Composition and Analysis, 23(1): 264-272.
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